Telephone-exchange apparatus.



No. 854,204. I PATENTED MAY 21, 1907.

' G.D.ENOGHS.

TELEPHONE EXCHANGE APPARATUS.

APPLIOATION FILED APB.24.1905- I I. a t V fife-ritzy.

IINITED STATES PATENT OFFICE.

CLAUDE D. ENocHs', or LA OROSSE, WISCONSIN, ASSIGNOR To THE VOTE- BERGER coMPflNY, A ooRPoRATIoN or WISCONSIN.

TELEPHONE-EXCHANGE APPARATUS.

I I Specification of Letters Patent.

Patented May 21, 1907.

Application filed April 24,1905. Serial 257,052-

telephone exchange apparatus of which the following is a full description, reference being had to the accompanying drawing forming part of this'specification. r My invention concerns the operation of telephone "circuits and more A particularly although not exclusively the subscribers line circuit and has for its object to-provide means for equalizing the resistance of telehone circuits of different lengths and workmg under different conditions so that a lamp or other signal and electrical devices requiring a constant current may be operated directly without the interpositionof relays.

,. Among the different features (if my in- .vention is embraced a sufficiently large steadying resistance or ballast in circuit with thesubscribers line conductor containing a line lamp, jack and. subscribers set whereby the resistance of the circuit when operated A is steadied, the voltage across the line lamp regulated, and the efficiency of. operationof the telephone a paratusincreased.

By the use vo my invention the line lamp is, protected and the employment of an ordinary line relay now generally used with telephone-systems isjnot necessary.

I In no other branch of the electrical art 1s there shown to exist any such arrangement of multitudinous in-c0ming lines, each with stance is there disclosed num rous separate circuits runningfrom substantially a common current source to different distances and each including a lamp or lam s or other electrical device in series and ba lasted so as to proortion the current to said lamp or device. eretofore the more common arrangements have been to employ line relays to control local lamp circuits or to insert fixed resistances in series with the lamps so that lam s on different lines receive substantially t e same current It has also beenusual to employ a source of current of sufiicient potential to operate the line ofa different resistance and rely upon artificial resistances in lines of lesser resistance to prevent too great a current on these latter llnes. It has'f'urther been common practice to employ larger wires for long lines. It however be noted that whatever 'means or device has been employed, it has been found necessary to separately test and classify so as to determine the necessary resistance to be added or the size of the wire to be used and since it has been too much labor and expense to have a different resistance or a different size of wire for each line, a certain grouping of lines of somewhere near the same resistance has been found necessary, and which has resulted only in a rough a proximation of compensatingresistance. hone of these resistances .vary'. The added resistance is always .the same and cannot inc ease its power to check any undue rise in current due to a sudden short'circuit of the lines and it is new in the telephone art to employ a resistance that'varies with the current. vention makes it possible to insert into each line a simple, inexpensive device in no manner made especially for that line, which automatically accommodates itself to that line.

and which can be. taken out and used on any other line of a different resistance and will automatically ballast this otherlinefand the devlice enables the line relays to be dispensed wit Y In the accompanying drawing is shown a diagrammatic View of a simple telephone exchange'system equipped with my invention, in which A represents the line circuit. To this cir-- cuit is shown connected the subscribers set or telephone B on one end anda line jack C, subsidiary signal or lamp D, battery E (in series) and'impedance coil F at the other end of said circuit; Associated with the line jack are the answering and calling plugs or cords G and their co-operating parts (all of ordinary'construjetion and familiar to. those skilled in the artto which this invention relates). In the'subscribers circuitis placed whatI have chosen to term a ballast H,

directly in series with 'the line lamps This ballast may be in the form of a conductor 2,

made of iron' w,ir e or other suitable material,

This inof the local drop or voltage in the exchange, the drop across the line lamp being somereceive the larger inclosed in a sealed chamber 3, which may or may not contain an inertgas, as preferred. The ballast conductor decreases inconduiztivity as its temperature rises; In casethe line has a hi n true resistance, the ballast receives .a small amount of current and its resistance Wlll be low; hence the line lamp will low true resistance the ballast will receive more current, its resistance willverymaterially use and the ballast will take up most what near 'what it was in caseof along subscribers line.

, rent. passing through said conductor isnot materially radiated and the corrective resistance and temperature of the ballast are thereby made extremely sensitive; It is ob-' vious that by this circuit containing. a bal-y last, as above employed no line relay is necessary, and the drop oi voltage in the line I flow of -c11rrent through the lines leading therefrom, a line signal and a ballast in series 90 lamp is regulated with great nicety.

WVhile I have shown only one form of 'ballast, it is obvious that other forms maybe used without departing from the spirit of this invention to effect the results set forth, and I do not wish to be understood as confining myself to the exact materials, construction or arrangement of parts described.

' Having described my invention, what I claim as new and desire to protect by Letters Patent, is:-

1. The combination with the'conductors of a telephone line, a source of current and a signaling instrument in circuit with said line and a ballast in circuit with said signaling in strument to regulate its voltage.

1 2. In combination with the conductors of a telephone line, a source of current in circuit with said line, a signaling lamp, and a steadying resistance in circuit with said lamp, for the purposes specified.

3. In combination with a telephone line circuit containing a signaling instrument at the central station, a ballast to steady the re- .sistance of said circuit under variation of the ment connected with said line circuit, and a steadying resistance in series with said signaling instrument, for the purposes SPBGlfiBd.

roportionof the local drop inside the exe ange. In case it has a The steadying resistance has 1 a large. positive temperature correction and flow in said line.

5. In combination with a telephone line circuit having a jack, a signaling lamp, and a ballast, all connected in series therewith.

6. The combination in telephone apparat us of the subscribers line circuit having a hne jack, battery, signaling lamp and'a ballast placed in series with said lamp and the line contact of said jack to regulate the vol I tage across said lamp. v

7. A telephone system having associated 7o therewith line circuits of divers resistances,

an electrical actuatingdevice, asou'rce of ..-current and an automatic ballast reslstance,

'for the purposes specified.

-,8. In a telephone system provided with line circuits, a sub station telephone set for each circuit, a common source of current supply, and a ballast adapted to be associated 5 with said' circuits and to be directly .afiected by the current flowing therein to introduce an. automatic compensating resistance proportionately to the amount 'of'current flow, whereby current may be maintained con stant in lines of various resistances, i

' 9; Ina telephone system,.a centr'alstation, 8

a subscriber's station, a line circuit interconnecting them, a source of current, means at the suhscrihers station to determine the with the line'circuit adapted to automatically vary proportionately to the current 10. In combination with the conductors of a telephoneline, a source of current and a ballast adapted to be included in said line, for the purposes specified 11. In comb' ation with the conductors of a telephone line, a source of. current, and a ballast composed of a conductor having a we highly sensitive temperature correction.

1.2. A telephone system, comprising in combination with the subscribers circuits, a

source of current, and a ballast composed of an iron wire conductor having a highly sensi- I0 5 tive temperaturacorrection. A

' 13. The c'ornbination with the conductors of a telephone line Aja line jack C, a s1gnaljing lamp D, a battery E and an impedance coil F, of a ballast H connected in series with 11 said lamp and the line contact of said jack, for the purposes specified.

In testimony'whereof I have signed my i name to this'specification in the presence of 

